Sprayer for application of textured finish to surfaces

ABSTRACT

A sprayer for providing a regulated flow of material to a gun includes apparatus for fixing a substantially-cylindrical stator to a circular port of a pump housing block. Such apparatus includes a pair of clips that are pivotally fixed to the exterior of the pump housing block. The clips are diagonally spaced with respect to the port. Apertures are arranged in the pump housing block to receive crimped portions of the clips to engage apertures within the surface of a collar fixed to an end portion of the stator. By fixing the stator to the pump housing block in a manner that is not subject to rotation, rotation of the rotor with respect to adhesive rubber material within the stator when torque is manually applied to the rotor.

REFERENCE TO RELATED APPLICATION

The present application is a continuation-in part of patent application Ser. No. 11/450,812 of inventor Eran Zagorsky titled “Sprayer For Application of Textured Finish to Surfaces” filed Jun. 12, 2006 in the United States Patent and Trademark Office.

BACKGROUND

1. Field of the Invention

The present invention relates to sprayers for use in the application of textured finishes to surfaces. More particularly, this invention pertains to a convenient and user-friendly sprayer unit for jobs of relatively-limited scope.

2. Description of the Prior Art

Texture spray equipment for use in small and medium size jobs that offers quick set-up, easy disassembly, compactness, portability and interchangeability of parts for quick, inexpensive repair has been developed over the years to address the inadequacies of bulky drywall material spraying systems for pumping liquids at job locations. Such bulky systems require mounting onto vehicles or trailers for ease of transportation and are characterized by, for example, large storage tanks that render their usage economical only for large jobs.

Examples of such spray equipment for smaller jobs include the sprayer taught by U.S. Pat. No. 5,967,426 of McLoed covering “Knockdown portable Liquid Drywall Material Spray System and Apparatus” and others. Such systems are typically mounted on a wheelable cart-like frame and interact with a compressor to provide a controllable spray of material for adhering onto a surface.

FIG. 1 is a schematic view of a generalized texture deposition system 10 of the type discussed above. The sprayer 11 of the sprayer system is indicated in broken outline. A hopper 12 is arranged to receive input material 14 for eventual deposition onto a surface. The material (e.g. drywall) 14 is transferred, generally by means of gravity feed, into a pump 16 of the screw-feed (rotor and stator) type. The pump 16 advances the received material 14 linearly toward a nozzle 18, in response to the output of an electric motor 20 whose speed and power are selectively controlled by means of a control box 22.

A hose 24 is fitted to the nozzle 18 to receive the material 14 at a predetermined flow rate. The material hose 24 feeds the flowing material to a gun 26. A second input to the gun 26 comprises an air flow generated by a compressor 28 and delivered through an air hose 30. The relative flow parameters of material 14 through the material hose 24 and air through the air hose 30 to the gun 26 determine the thickness and texture of the resultant material deposited upon a surface.

While texture deposition systems as described above may be configured for suitability for small and medium sized jobs, such equipment is often not user friendly. Although relatively portable, operation of such wheeled equipment is complicated by such limitations as spillage of material from the hopper 12 and shorting of the circuitry of the control box 22 as a result of weather. Furthermore, the sprayer 11 often requires disassembly of the pump 16 after period of extended non-use as a result of adhesion of the internal rotor to a surrounding layer of rubber within the stator.

SUMMARY OF THE INVENTION

The present invention addresses the preceding and other shortcomings of the prior art by providing apparatus for fixing an elongated, substantially-cylindrical stator to a pump housing block of a sprayer.

Such apparatus includes a collar fixed exterior and adjacent an end of the stator. The collar has at least one indentation arranged about the circumference of the stator. At least one clip that includes a crimped portion is pivotally engaged to the exterior of the pump housing block.

At least one aperture is provided in the pump housing block. Such aperture is located with respect to a clip so that the crimped portion of the pivotally-mounted clip protrudes within the interior of the pump housing block when the clip is rotated to a closed position to engage an indentation of the collar.

The foregoing and other features of the invention will become further apparent from the detailed description below. Such description is accompanied by a set of drawing figures. Numerals of the drawing figures, corresponding to those of the written description, point to the features of the invention with like numerals referring to like features throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a sprayer system in accordance with the prior art;

FIGS. 2 a through 2 c are a perspective view, a partially exploded side elevation view and an exploded perspective view of the cover assembly, respectively, of a sprayer in accordance with an embodiment of the invention;

FIGS. 3 a through 3 c are a side sectional view of the pump, a frontal view of the free end of the cartridge shaft and an enlarged exploded perspective view of the relationship of the pump to the stator assembly respectively, of a sprayer in accordance with an embodiment of the invention;

FIGS. 4 a and 4 b are perspective views in juxtaposition of the hopper and the transport frame, respectively, of a sprayer in accordance with an embodiment of the invention; and

FIG. 5 is a perspective view of a removable control box engaged to the frame of a sprayer in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 2 a through 2 c are a perspective view, a partially exploded side elevation view and an exploded perspective view of the cover assembly, respectively, of a sprayer in accordance with an embodiment of the invention. Such a sprayer includes numerous user-friendly features that facilitate maintenance, portability and usability. As a result, the device of the invention further advances the ability of a user to complete low volume texturizing jobs in an efficient manner and absent the “overkill” of large-scale systems.

As seen in FIG. 2 a, the sprayer 32 comprises two main functional units, a hopper 34 for receiving material and pump 36 whose operation is powered by an electric motor 38. (A control box for controlling the operation of the motor 38 cannot be seen in FIG. 2 a but is described and illustrated below.) The entire sprayer assembly is mounted on a frame 40 that includes a pair of wheels 42 (only one of which is visible in FIG. 2 a) that are aligned and rotatable about a common axis 44. The tubular frame 40 includes legs 46, 48 for stabilizing the sprayer 32 at rest and a handle for facilitating ready transport. As will be seen below, the hopper 34 is designed to facilitate transport of the sprayer 32 despite the presence of material within the hopper 34 while the design of the frame 40 facilitates the cooperative engagement of a removable control box, thereby permitting the sprayer 32 to be left outside during inclement weather that would otherwise subject the control electronics of the sprayer 32 to damage.

A guard 52 overlies the mechanism whereby the output of the motor 38 drives the pump 36. Such mechanism will be appreciated by additional reference to FIGS. 2 b, a partially-exploded side elevation view of the sprayer 32, and 2 c, an exploded perspective view of the guard 52 including associated mechanisms. Referring to FIGS. 2a through 2 c now in combination, the motor 38 is fixed to a bracket mount 54 so that the output drive shaft 56 of the motor is arranged to protrude through a v-shaped opening 58 at the bottom of an inner cover 60 that includes a peripheral edge 61. A planar outer cover 62 is fixed to the inner cover by means of cap screws 64 whereby opposed planar surfaces of the inner and outer covers 60, 62 are maintained in parallel spacing defined by the height of the peripheral edge 61 of the inner cover 60.

A mentioned earlier, the drive shaft 56 of the motor 38 is aligned to protrude within the region formed between the inner and outer covers 60 and 62 at the v-shaped opening 58. A small gear is fixed to the end of the drive shaft 56 to engage a timing belt 68 for driving a large gear wheel 70. The large gear wheel 70 will be seen below to be fixed to an end of a drive train for driving the pump 36.

An annular hub 72 is located at the center of the large gear wheel 70 for coupling to a cartridge shaft (not shown) at the end of the drive train of the pump. A upper aperture 74 within the rear cover 60 is aligned with both the center of the annular hub 72 and with an aperture 76 within the front cover 62. As a result, the end of the cartridge shaft is aligned with the aperture 76 when fixed to the annular hub 72. Accordingly, the end of the cartridge shaft is thereby accessible, through the aperture 76 of the front cover 62, without disassembly of the guard 52.

Reference is now made to FIGS. 2 b and 3 a, a side sectional view of the pump 36 of a sprayer in accordance with an embodiment of the invention, in combination. As can be seen, the pump 36 includes a pump pump housing block 78 having an upstanding input port 80 for receiving gravity-fed material from the overlying hopper 34. A cartridge tube 82 and a stator 84 are engaged to opposed ends of the pump housing block 78. The pump housing block 78 includes an internal elongated passageway 86 within which is located a pump drive train comprising, in combination, aligned elongated elements including a rotor 88, a connecting rod 90 and a cartridge shaft 92. The cartridge shaft 92 comprises and elongated member consisting of three adjoining cylindrical elements of successively reduced diameter (when one proceeds outwardly from the interior of the pump housing block 78). It is centered for rotation within the internal elongated passageway 86 of the pump housing block 78 by means of an inner bearing 94 and an outer bearing 96.

The connecting rod 90 is joined to the cartridge shaft 92 and to the rotor 88 by means of dowel pins 98, 100. The stator 84, of conventional design, includes a filled rubber interior 101 within which the rotor 88 is aligned for rotation along the central axis of the elongated internal passageway 86 of the pump housing block 78. Accordingly, the axes of rotation of the elongated rotor 88, the connecting rod 90 and the cartridge shaft 92 are aligned within the pump housing block 78. A collar 102 of molded elastomeric material surrounds the end portion of the stator 84 that seats within the pump housing block 78. The collar 102 is rigidly fixed to the stator 84 by a combination of threading and adhesive, effectively forming a single piece, discussed below.

The free end 103 of the cartridge shaft 92 is polygonal, preferably hexagonally-shaped as seen in FIG. 3b, a frontal view of the free end of the cartridge shaft 92. In the prior art, the rubber of the filled rubber interior 101 of the standard stator 88 is known to adhere to the rotor 88 during periods of non-use. As a consequence, disassembly of the pump 36 has been required to render the sprayer operational. Such disassembly can be tedious and time-consuming. To overcome this difficulty, the free end 103 of the cartridge shaft 92 comprises a polygonal shape in the present invention that may be engaged by an appropriately-shaped socket wrench. Further, the cylinder shaft 92 is positioned in alignment with the aperture 76 within the outer cover 62 of the guard 52. As result, the free end 103 may be engaged by such a socket wrench without any disassembly. Once so engaged, the user can free the rotor from adhesion to the filled rubber interior 101 of the stator 84 by applying manual (or mechanical) force to the wrench to cause the entire aligned, elongated pump drive assembly comprising the cylinder shaft 92, the connecting rod 90 and the rotor 88 to rotate the rotor 88 a sufficient amount with respect to the filled rubber interior 101 to break the adhesion force.

The relationship between the pump housing block 78 and the stator 84 (with collar 102 fixed thereto) is illustrated in the exploded perspective view of FIG. 3 c. As shown, the molded collar 102 includes a plurality (four) of partially-circumferential indentations 104. Such indentations 104 are arranged to accommodate the crimped portions 106 of clamps 108 that are pivotally-mounted to the exterior of the pump housing block 78. Apertures are 110 provided in the body of the pump housing block 78 to admit the crimped portions 106 of the clamps 108 when rotated to their “closed” positions (the clamp 108 is illustrated in the “open” position in FIG. 3 c).

The stator 84 is fixed to a circular port of the pump housing block 78 by insertion of the end that includes the molded collar 102 with the clamps 108 in the open position illustrated in FIG. 3 c. This is followed by rotation of the collar 102 (and stator 84) to assure that slots 104 are aligned with the apertures 110 for admitting the crimped portions 106 of the clamps 108. Thereafter, the pivotally-mounted clamps 108 are rotated to their closed positions whereby the crimped portions 106 protrude through the apertures 110 into aligned peripheral indentations 104 of the collar 102. Thus, the substantially-cylindrical stator 84, held and releasable by means of the clamps 108, is readily insertable and removable with respect to the pump housing block 78 via pure axial movement along its axis of symmetry. By securing the stator 84 to the pump housing block 78 by means of the clamps 108 that seat in indentations 104 that block potential rotation of the stator 84, rather than threadedly engaging stator 84 and pump housing block 78, the stator 84 is prevented from rotating in response to rotational forces transmitted from the rotor 88 via the filled rubber interior 101 of the stator 84. Such forces can be transmitted when, through a long period of non-use of the sprayer, the filled rubber interior 101 is caused to adhere to the surfaces of the rotor 88 and the stator 84. Should such adhesion of the filled rubber interior 101 cause the stator 84 to rotate with the rotor 88, material cannot be advanced through the stator 84, causing the sprayer to cease to function.

FIGS. 4 a and 4 b are perspective views in juxtaposition of the hopper and the transport frame of a sprayer in accordance with an embodiment of the invention. The hopper 34 comprises an integral molded structure of plastic or other synthetic composition that defines a volume within an interior bounded by a front panel 112, opposed side panels 114 and 116, and a rear panel 118. The height of the rear panel 118 exceeds that of the front panel 112. Accordingly, the edges of side panels 114 and 116 that intersect the rear panel 118 are of greater than those that intersect the front panel 112 as shown. A lid 120 protrudes from the top of the rear panel 118 and adjoins the extended regions of the side panels 114, 116 having heights approximately equal to that of the rear panel 118.

Viewing the hopper 34 in conjunction with the juxtaposed frame 40, one can see that the hopper 34 is aligned with respect to the transport frame so that the rear panel 118 lies against upstanding tubular frame members 122, 124 that define the back of the frame 40. Such members 122, 124 are positioned to rotate about the axle 44 common to the paired wheels 42. The permits the user to transport the sprayer by rotating the handle 50 downwardly and pushing the device. The lid 120 that covers the rear portion of the hopper 34 prevents the overflow of material from the hopper 34 during such transport. Thus, unlike other knockdown sprayers, one may relocate the sprayer of the invention without first emptying the hopper of drywall or other material prior to manual transport. This additionally simplifies and facilitates the use of the invention.

As can be seen in FIG. 4 b, a generally u-shaped flange member 126 is fixed to the handle 50 of the frame 40. Such member 126 is provided for engaging a mounting bracket 128 fixed to a control box 130 as illustrated in FIG. 5. The control box 130 provides the switches for adjusting the direction and speed of the electric motor 38 that, in turn, controls operation of the pump 36. While of standard design, it is significant that the control box 130 of a sprayer in accordance with an embodiment of the invention is fully removable, allowing its ready removal upon decoupling of associated cabling 132 from other elements of the sprayer. This permits one to then lift the control box 130 from the generally u-shaped flange 128 at the rear of the frame 40 for interior storage while the sturdy remainder of the sprayer is left outside. Again, this feature, a control box 130 removably fixed to the frame of the sprayer, further facilitates the use of the invention.

Thus it is seen that the present invention provides a user friendly sprayer of the knockdown type. By employing a sprayer in accordance with the claimed invention, the user enjoys numerous user-friendly features. Such features avoid any need to disassemble the sprayer pump after periods of prolonged non-use, permit manual transport of the sprayer while drywall or other material is present in the hopper and allow the device to be left outside during inclement weather.

While the invention has been described with reference to a presently-preferred embodiment, it is not limited thereto. Rather, the invention is limited only insofar as it is defined by the following set of patent claims and includes within its scope all equivalents thereof. 

1. Apparatus for fixing an elongated, substantially-cylindrical stator to a pump housing block of a sprayer comprising, in combination: a) a collar, said collar being fixed exterior and adjacent an end of said stator; b) said collar having at least one indentation arranged about the circumference of said stator; c) at least one clip pivotally engaged to the exterior of said pump housing block; d) said at least one clip including a crimped portion; e) at least one aperture in said pump housing block, said aperture being located with respect a clip so that said crimped portion of said pivotally-mounted clip protrudes within the interior of said pump housing block when said clip is rotated to a closed position to engage an indentation of said collar.
 2. Apparatus as defined in claim 1 further comprising: a) a plurality of indentations; b) a plurality of pivotally-mounted clips; and c) a plurality of apertures in said pump housing block.
 3. Apparatus as defined in claim 2 further including: a) two pivotally-mounted clips; and b) two apertures in said pump housing block, each of said apertures being aligned to admit said crimped portion of one of said pivotally-mounted clips.
 4. Apparatus as defined in claim 3 further characterized in that: a) said collar is substantially annular; b) said pump housing block includes a circular port for receiving said collar; and c) said clips are spaced diagonally from one another with respect to said circular port of said pump housing block.
 5. Apparatus as defined in claim 4 wherein said collar comprises molded elastomeric material.
 6. Apparatus as defined in claim 5 wherein said collar includes four indentations. 